<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package    CodeIgniter
 * @author    EllisLab Dev Team
 * @copyright    Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright    Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
 * @license    https://opensource.org/licenses/MIT    MIT License
 * @link    https://codeigniter.com
 * @since    Version 3.0.0
 * @filesource
 */
defined('BASEPATH') or exit('No direct script access allowed');

/**
 * CodeIgniter Redis Caching Class
 *
 * @package       CodeIgniter
 * @subpackage Libraries
 * @category   Core
 * @author       Anton Lindqvist <anton@qvister.se>
 * @link
 */
class CI_Cache_redis extends CI_Driver
{
    /**
     * Default config
     *
     * @static
     * @var    array
     */
    protected static $_default_config = array(
        'socket_type' => 'tcp',
        'host' => '127.0.0.1',
        'password' => null,
        'port' => 6379,
        'timeout' => 0,
    );

    /**
     * Redis connection
     *
     * @var    Redis
     */
    protected $_redis;

    /**
     * An internal cache for storing keys of serialized values.
     *
     * @var    array
     */
    protected $_serialized = array();

    /**
     * del()/delete() method name depending on phpRedis version
     *
     * @var    string
     */
    protected static $_delete_name;

    // ------------------------------------------------------------------------

    /**
     * Class constructor
     *
     * Setup Redis
     *
     * Loads Redis config file if present. Will halt execution
     * if a Redis connection can't be established.
     *
     * @return    void
     * @see        Redis::connect()
     */
    public function __construct()
    {
        if (!$this->is_supported()) {
            log_message('error', 'Cache: Failed to create Redis object; extension not loaded?');
            return;
        }

        isset(static::$_delete_name) or static::$_delete_name = version_compare(phpversion('phpredis'), '5', '>=')
        ? 'del'
        : 'delete';
        //add by fpq 20200517,目前使用phpredis5，强制使用del
        static::$_delete_name = 'del';
        $CI = &get_instance();

        if ($CI->config->load('redis', true, true)) {
            $config = array_merge(self::$_default_config, $CI->config->item('redis'));
        } else {
            $config = self::$_default_config;
        }

        $this->_redis = new Redis();

        try
        {
            if ($config['socket_type'] === 'unix') {
                $success = $this->_redis->connect($config['socket']);
            } else // tcp socket
            {
                $success = $this->_redis->connect($config['host'], $config['port'], $config['timeout']);
            }

            if (!$success) {
                log_message('error', 'Cache: Redis connection failed. Check your configuration.');
            }

            if (isset($config['password']) && !$this->_redis->auth($config['password'])) {
                log_message('error', 'Cache: Redis authentication failed.');
            }
        } catch (RedisException $e) {
            log_message('error', 'Cache: Redis connection refused (' . $e->getMessage() . ')');
        }
    }

    // ------------------------------------------------------------------------

    /**
     * Get cache
     *
     * @param    string    $key    Cache ID
     * @return    mixed
     */
    public function get($key)
    {
        $key = $this->seriaKey($key);

        $value = $this->_redis->get($key);

        if ($value !== false && $this->_redis->sIsMember('_ci_redis_serialized', $key)) {
            return unserialize($value);
        }

        return $value;
    }

    // ------------------------------------------------------------------------

    /**
     * set cache
     *
     * @param    string    $id    Cache ID
     * @param    mixed    $data    Data to save
     * @param    int    $ttl    Time to live in seconds
     * @param    bool    $raw    Whether to store the raw value (unused)
     * @return    bool    TRUE on success, FALSE on failure
     */
    public function set($id, $data, $ttl = 60, $raw = false)
    {
        $id = $this->seriaKey($id);

        if (is_array($data) or is_object($data)) {
            if (!$this->_redis->sIsMember('_ci_redis_serialized', $id) && !$this->_redis->sAdd('_ci_redis_serialized', $id)) {
                return false;
            }

            isset($this->_serialized[$id]) or $this->_serialized[$id] = true;

            $data = serialize($data);
        } else {
            $this->_redis->srem('_ci_redis_serialized', $id);
        }

        return $this->_redis->set($id, $data, $ttl);
    }

    // ------------------------------------------------------------------------

    /**
     * Delete from cache
     *
     * @param    string    $key    Cache key
     * @return    bool
     */
    public function delete($key)
    {
        $key = $this->seriaKey($key);

        if ($this->_redis->{static::$_delete_name}($key) !== 1) {
            return false;
        }

        $this->_redis->srem('_ci_redis_serialized', $key);

        return true;
    }

    // ------------------------------------------------------------------------

    /**
     * Increment a raw value
     *
     * @param    string    $id    Cache ID
     * @param    int    $offset    Step/value to add
     * @return    mixed    New value on success or FALSE on failure
     */
    public function increment($id, $offset = 1)
    {
        $id = $this->seriaKey($id);
        return $this->_redis->incrBy($id, $offset);
    }

    // ------------------------------------------------------------------------

    /**
     * Decrement a raw value
     *
     * @param    string    $id    Cache ID
     * @param    int    $offset    Step/value to reduce by
     * @return    mixed    New value on success or FALSE on failure
     */
    public function decrement($id, $offset = 1)
    {
        $id = $this->seriaKey($id);
        return $this->_redis->decrBy($id, $offset);
    }

    // ------------------------------------------------------------------------

    /**
     * Clean cache
     *
     * @return    bool
     * @see        Redis::flushDB()
     */
    public function clean()
    {
        return $this->_redis->flushDB();
    }

    // ------------------------------------------------------------------------

    /**
     * Get cache driver info
     *
     * @param    string    $type    Not supported in Redis.
     *                Only included in order to offer a
     *                consistent cache API.
     * @return    array
     * @see        Redis::info()
     */
    public function cache_info($type = null)
    {
        return $this->_redis->info();
    }

    // ------------------------------------------------------------------------

    /**
     * Get cache metadata
     *
     * @param    string    $key    Cache key
     * @return    array
     */
    public function get_metadata($key)
    {
        $key = $this->seriaKey($key);
        $value = $this->get($key);

        if ($value !== false) {
            return array(
                'expire' => time() + $this->_redis->ttl($key),
                'data' => $value,
            );
        }

        return false;
    }

    // ------------------------------------------------------------------------

    /**
     * Check if Redis driver is supported
     *
     * @return    bool
     */
    public function is_supported()
    {
        return extension_loaded('redis');
    }

    // ------------------------------------------------------------------------

    /**
     * Class destructor
     *
     * Closes the connection to Redis if present.
     *
     * @return    void
     */
    public function __destruct()
    {
        if ($this->_redis) {
            $this->_redis->close();
        }
    }

    /**
     * [keys 获取相仿key]
     * @Description 使用*可查出相仿的keys;默认自动右侧加*
     * @Author      FengPQ
     * @DateTime    2020-05-17T23:56:27+0800
     * @param       [type]                   $param [参数]
     * @return      [type]                          [description]
     */
    public function keys($param, $is_default = true)
    {
        $param = $this->seriaKey($param);
        if ($is_default) {
            $param .= '*';
        }

        return $this->_redis->keys($param);
    }

    /**
     * [exists 验证指定的键是否存在]
     * @ckhero
     * @DateTime 2016-06-17
     * @param [type] $name [缓存名字]
     * @return [type] [返回 存在（true）/不存在（false）]
     */
    public function exists($name)
    {
        $name = $this->seriaKey($name);
        return $this->_redis->exists($name);
    }

    /**
     * [ttl description]
     * @Description redis剩余存活时间
     * @Author      FengPQ
     * @DateTime    2020-05-20T22:30:02+0800
     * @param       [type]                   $name [description]
     * @return      [type]                         [description]
     */
    public function ttl($name)
    {
        $name = $this->seriaKey($name);
        return $this->_redis->ttl($name);
    }

    /**
     * [expire 设置过期时间]
     * @ckhero
     * @DateTime 2016-08-16
     * @param [type] $data [二维数组array( array('键值'=>过期时间))]
     * @return [type] [description]
     */
    public function expire($key, $val = false)
    {
        if (is_array($key) && !$val) {
            $data = $this->seriaKey($key);
        } else if (!is_array($key)) {
            $data[$key] = $val;
        }

        foreach ($data as $k => $expire_time) {
            $this->_redis->expire($k, $expire_time);
        }
        return true;
    }

    /**
     * [checkKey description]
     * @Description key为数组情况，自动改为序列化
     * @Author      FengPQ
     * @DateTime    2020-05-18T23:26:43+0800
     * @param       [type]                   $key [description]
     * @return      [type]                        [description]
     */
    private function seriaKey($key)
    {
        if (is_array($key) or is_object($key)) {
            $temp = '';
            if (deep_in_array(FLAG, $key)) {
                $temp = $key[FLAG];
                unset($key[FLAG]);
            }
            $key = serialize(ksort($key)) . $temp;
        }
        return $key;
    }

}
